The present invention relates to gas turbine engines, and in particular to a deoiler for a lubrication system of a gas turbine engine.
Gas turbine engines typically include lubrication systems for providing lubricating liquid, such as oil, to various components of the gas turbine engine such as gears and bearings. Lubrication systems typically supply the oil to the components to cool and lubricate the components and then scavenge used oil from the components, to be cooled, filtered, and supplied again to those components. When the lubricating liquid is scavenged from those components, the lubrication system can scavenge a mixture of oil and air. Particle laden air can be supplied to a deoiler to separate the oil from the air.
In some lubrication systems, a rotating deoiler is positioned in a housing and includes a rotating shaft that interfaces with an outlet of the housing. If the housing is pressurized, oil laden air can undesirably escape between the rotating shaft and the housing. It can be difficult and expensive to adequately seal the interface between the rotating shaft and the housing. Moreover, seals can be wear-prone and can be expensive and time-consuming to replace. Bleed air can be provided to back-pressure the seal to reduce the amount of escaping oil; however providing this air can undesirably reduce engine efficiency.